Whereas the beautiful is limited, the sublime is limitless, so that the mind in the presence of the sublime, attempting to imagine what it cannot, has pain in the failure but pleasure in contemplating the immensity of the attempt.

Ingratitude is the essence of vileness.

Two things awe me most, the starry sky above me and the moral law within me.

It is not necessary that whilst I live I live happily; but it is necessary that so long as I live I should live honourably.

May you live your life as if the maxim of your actions were to become universal law.

Immaturity is the incapacity to use one's intelligence without the guidance of another.

Metaphysics is a dark ocean without shores or lighthouse, strewn with many a philosophic wreck.

Two things fill the mind with ever new and increasing wonder and awe - the starry heavens above me and the moral law within me.

Morality is not the doctrine of how we may make ourselves happy, but how we may make ourselves worthy of happiness.

We are not rich by what we possess but by what we can do without.

In law a man is guilty when he violates the rights of others. In ethics he is guilty if he only thinks of doing so.

Always recognize that human individuals are ends, and do not use them as means to your end.

Act that your principle of action might safely be made a law for the whole world.

Perpetual peace is only found in the graveyard.

Nothing is divine but what is agreeable to reason.

A categorical imperative would be one which represented an action as objectively necessary in itself, without reference to any other purpose.

The only objects of practical reason are therefore those of good and evil. For by the former is meant an object necessarily desired according to a principle of reason; by the latter one necessarily shunned, also according to a principle of reason.

Man must be disciplined, for he is by nature raw and wild.

It is not God's will merely that we should be happy, but that we should make ourselves happy.

Science is organized knowledge. Wisdom is organized life.

Thoughts without content are empty, intuitions without concepts are blind.

So act that your principle of action might safely be made a law for the whole world.

What can I know? What ought I to do? What can I hope?

But although all our knowledge begins with experience, it does not follow that it arises from experience.

Seek not the favor of the multitude; it is seldom got by honest and lawful means. But seek the testimony of few; and number not voices, but weigh them.

Out of timber so crooked as that from which man is made nothing entirely straight can be carved.

Act in such a way that you treat humanity, whether in your own person or in the person of any other, never merely as a means to an end, but always at the same time as an end.

All the interests of my reason, speculative as well as practical, combine in the three following questions: 1. What can I know? 2. What ought I to do? 3. What may I hope?

Even philosophers will praise war as ennobling mankind, forgetting the Greek who said: 'War is bad in that it begets more evil than it kills.'

All thought must, directly or indirectly, by way of certain characters, relate ultimately to intuitions, and therefore, with us, to sensibility, because in no other way can an object be given to us.

By a lie, a man... annihilates his dignity as a man.

Religion is the recognition of all our duties as divine commands.

Live your life as though your every act were to become a universal law.

Intuition and concepts constitute... the elements of all our knowledge, so that neither concepts without an intuition in some way corresponding to them, nor intuition without concepts, can yield knowledge.

Out of the crooked timber of humanity, no straight thing was ever made.

It is beyond a doubt that all our knowledge that begins with experience.

All our knowledge begins with the senses, proceeds then to the understanding, and ends with reason. There is nothing higher than reason.

If man makes himself a worm he must not complain when he is trodden on.

I had therefore to remove knowledge, in order to make room for belief.

He who is cruel to animals becomes hard also in his dealings with men. We can judge the heart of a man by his treatment of animals.

Have patience awhile slanders are not long-lived. Truth is the child of time erelong she shall appear to vindicate thee.

Happiness is not an ideal of reason, but of imagination.

From such crooked wood as that which man is made of, nothing straight can be fashioned.

Freedom is independence of the compulsory will of another.

Experience without theory is blind, but theory without experience is mere intellectual play.